This is a Swoopula. Swoopulas attack from the air and cling to you to suck your HP. Max HP: 8, Attack Power: 2, Defense Power: 0 Hit repeatedly to fight it off or else it'll keep sucking your HP. You can't jump high enough to attack them while they're hanging from the ceiling. An earthquake attack ought to work, though. Flying party members, like Bow or Parakarry, can also attack them with ease. If they fall and begin to flap around, you can attack them by jumping as well.